Oh yes...good to see the collective IQ of WTF is continuing its downward spiral towards complete retardation. First off, if you do take a cricket bat to his shins, you WILL get caught. You have sufficient motive, and unless your ex-friend is blind, deaf and dumb, he WILL telll the police you did it. So...
Stoner Friend: Fine + Rehabiltation order for theft.
You: 6-12months in Juvi/Prison for GBH (If first offence)
If you're going to try to get him back at least try and be clever about it.