I recently got the logos on mine painted over. I did it at Inflatable Technologies: Inflatable Raft Repair Specialists - Boat Repair
It was about $100, looks great. It is a relief not to have people asking me if I'm commercial at every single put-in.
The other option they offered was to remove the logos. They use oven cleaner. They are pros and they've done it plenty of times so I'm sure they'd do a good job with removal but I chose to have them paint over it.
The way I figure it, a perfect removal would still show the shadow of the logo (because of UV fading of the raft) so I'd rather just add a rectangle of rubber paint over the logo. The color doesn't match perfectly but it almost looks like some kind of original design feature, like an extra layer of skid protection on the sides of the tubes or something.
I'm sure you could do it cheaper yourself but I'm at the point that I would rather pay someone $100 than spend an entire day cussing in my garage.