1. Go to:
Win -> %appdata%/solaris/
You can do so by opening Explorer and typing that into the path field.
Mac -> ~/Library/Application Support/Solaris/
To find the folder on Mac:
put: ~/Library/Application Support/Solaris
then click GO
2. Copy wallet.dat to a safe place like a USB drive
IF YOU ARE RUNNING MASTERNODE(S)
Also copy the masternode.conf file.
Paste both files into the same folder on new PC.