HL2 Story Models Playable in Deathmatch

Is it possible without making a whole mod or using XSI? If so, how?

I highly doubt this

Perhaps you can replace the standard deathmatch models with the single
player character models, but that will require some modelling work.
Probably some bones names and stuff that need to be changed, but I'm
not yet familiar with HL2 modelling, so I can't really say anything
more about it...