Update v1.2-instruction.md

Author: raullenchai

changelog/v1.2-instruction.md

@@ -1,7 +1,6 @@
 
-## Instruction for mainnet v1.2.0 upgrade
-First, go to the `iotex-var` folder on your node (where it has 3 sub-folders
-`etc`, `data`, `log`)
+## Instruction for Mainnet v1.2.0 Upgrade
+First, go to the `iotex-var` folder on your node (where it has 3 sub-folders `etc`, `data`, `log`)
 ```
 export IOTEX_HOME=$PWD
 ```
@@ -11,7 +10,7 @@ docker stop iotex
 docker rm iotex
 ``` 
 
-#### Option 1: (node running without API gateway)
+#### Option 1 - if you are running the node WITHOUT API gateway enabled
 Check files under `$IOTEX_HOME/data`, if you don't see a file named `index.db`,
 then your node is **not** running as gateway. In this case, simply start the
 node using image v1.2.0.
@@ -29,12 +28,10 @@ docker run -d --restart on-failure --name iotex \
         -genesis-path=/etc/iotex/genesis.yaml
 ```
 
-If your node is syncing blocks very slow, see [here](#slow-sync)
+**If your node is syncing blocks very slow, see [here](#slow-sync)**
 
-#### Option 2: (node running as API gateway)
-Otherwise, the node is running as a gateway. In this case, you'll need to wipe
-out the data and start from latest snapshot, due to some index file in v1.2 is
-not backward-compatible.
+#### Option 2 - if you are running the node WITH API gateway enabled
+In this case, you'll need to wipe out the data and start from latest snapshot, due to index file in v1.2 is not backward-compatible.
 ```
 rm -rf $IOTEX_HOME/data
 curl -L https://t.iotex.me/mainnet-data-with-idx-latest > $IOTEX_HOME/data.tar.gz
@@ -61,40 +58,41 @@ recommend you do the upgrade in an epoch when the node is not chosen as active
 delegate. This would prevent your node from being possibly probated and lose
 productivity.
 
-If your node is syncing blocks very slow, see [here](#slow-sync)
+**If your node is syncing blocks very slow, see [here](#slow-sync)**
 
-## Instruction for testnet v1.2.0 upgrade
-To upgrade to testnet v1.2.0, the procedure is same as that of mainnet, except
-these 2:
+## Instruction for Testnet v1.2.0 Upgrade
+To upgrade to testnet v1.2.0, the procedure is same as that of mainnet, except these 2:
 
-1. In Option 2, download the snapshot from `https://t.iotex.me/testnet-data-with-idx-latest`
-2. Run Step 0 below first
+1. Download the snapshot from `https://t.iotex.me/testnet-data-with-idx-latest` if needed
+2. Update the config and genesis files like below
 
-#### Step 0:
-1. Save the private key and external IP address, i.e., the `producerPrivKey:`
-and `externalHost` line in file `$IOTEX_HOME/etc/config.yaml`
-2. Upgrade the config and genesis yaml
-```
-curl https://raw.githubusercontent.com/iotexproject/iotex-bootstrap/v1.2.0/config_testnet.yaml > $IOTEX_HOME/etc/config.yaml
-curl https://raw.githubusercontent.com/iotexproject/iotex-bootstrap/v1.2.0/genesis_testnet.yaml > $IOTEX_HOME/etc/genesis.yaml
+  * Save the private key and external IP address, i.e., the `producerPrivKey:` and `externalHost` line in file `$IOTEX_HOME/etc/config.yaml`
 
-```
-set the private key and external IP back into `$IOTEX_HOME/etc/config.yaml`, then
-continue onto Option 1 or 2.
+  * Get the new config and genesis files
+  ```
+  curl https://raw.githubusercontent.com/iotexproject/iotex-bootstrap/v1.2.0/config_testnet.yaml > $IOTEX_HOME/etc/config.yaml
+  curl https://raw.githubusercontent.com/iotexproject/iotex-bootstrap/v1.2.0/genesis_testnet.yaml > $IOTEX_HOME/etc/genesis.yaml
+  ```
+
+  * Set the private key and external IP back into `$IOTEX_HOME/etc/config.yaml`
+
+
+**If your node is syncing blocks very slow, see [here](#slow-sync)**
+
+### <a name="slow-sync"/>Troubleshoot for Slow Sync
 
-If your node is syncing blocks very slow, see [here](#slow-sync)
+Under certain network conditions, the node may sync slower as it should be. Follow the steps below to config it the sync mechanism to be more aggresive.
 
-#### <a name="slow-sync"/>solution for slow-sync
-stop the node
+1. stop the node
 ```
 docker stop iotex
 ```
-open file `$IOTEX_HOME/etc/config.yaml`, add the following line under
+2. open file `$IOTEX_HOME/etc/config.yaml`, add the following line under
 `blockSync:`
 
 ![image](/changelog/sync-interval.png)
 
-restart the node
+3. restart the node
 ```
 docker restart iotex
 ```