Evening bigglez
If you want to drop charges against your Uncle, if circumstances have changed with him now and you are getting on with him as '09 a long time ago, for example, and he regrets what he did and has apologised to you etc......nothing to stop you ...just advise your solicitor...he/she will do the rest........BUT if the police decide to go ahead, he could get a suspended sentence for GBH if they go ahead with the prosecution, or maybe a fine. Highly unlikely the judge will give him jail time, so up to you really, mate.
There again...if you AND the 3 remaining police officers continue to prosecute, it could be more likely that your Uncle will face prison time.
Hope you sort it out, bigglez and do whats best for the family too. :0)