So basically, you want to get stronger, but not make an effort out of it? Just swap out Stealth and Contacts for more concept-fitting skills at milestones and up your skills the normal way. Just because he got his arse handed to him, doesn't automatically make him more in control of himself of more sure of himself.
That means it's up to you and the GM to decide how to handle this. I don't know how long this game has been running, or how experienced you are with DFRPG, but if your character has only a few sessions under his belt, it is easier to justify, then when he has had a major milestone. Secondly, if you have experience with creating DFRPG characters, then you might expect less forgiveness from a GM.
The reason I think like this, is that you must have had some ideas as to why your character 'needed' Stealth or Contacts and now it seems you just decided you want to lose them to become more powerful without effort. Mind you, I say it seems like this, from your posts. It is a feeling and it might be wrong.
As an aside, I believe you meant page 91 about totally revising a character. If you want to do that, why not simply ask your GM that? Finally, just say you got a rather powerful bump on the head and you no longer have the ability for subtlety anymore, losing both skulking and friends because of that...