For windows only.
Backup the wallet.dat file. IF this is backed up already on USB stick then you skip this step.
You can find this by doing. Open up run command (Windows key + R)
Type in box and press enter
%appdata%
When this opens you will have a folder in there called redcoin (If you cant see these folders they are hidden . You need to change the folders settings to view system files. Google will help you)
Inside this folder is the wallet.dat (This holds the information and coins) Copy this somewhere safe.
Now delete this folder completely.
Uninstall the wallet application from the control panel.
Install the new wallet with the new .exe
Open wallet and let it sync completely.
Close wallet.
Go back and get to the %appdata% folder.
You will now see a new redcoin folder with a new wallet.dat file
Now copy your backed up wallet file into this folder and overwrite it.
Open wallet it should show the coins.
this does not work - i let the wallet fully sync, deleted new wallet.dat and restored backup wallet.dat and I get an error straight away
Assertion Failed! Expression: mapBlockIndex.count(hashSyncCheckPoint)