Has anyone converted an older MK trolling motor to the I Pilot

Have a saltwater version on my boat and was thinking about the I Pilot and I see you can buy the I Pilot and just replace the head on the TM

How hard is this and does it compromise the waterproof ability of the motor

Few years back I had to have the internal compass replaced in mine and it was done at a local service rep for MK

Also how well does the I-Pilot work (do a lot of trolling live bait for stripers and also long lining for crappie) and was thinking this would be better than anchoring up to fish brush piles

Fish out of a 21'CC so the anchoring takes a little time to get right sometimes