main centre case change on S9650 servo

[boos boy]

Hi, I have the opportunity to buy a couple of used S9650 servos from a heli so they have no side lugs for mounting flat on the chassis. I have found a place I can buy new cases, but how easy is it to change the main body of the servo, I read somewhere I have to fully strip the servo down and the motor is glued in? I can get the servos for a little as £15 but it is worth it and anyone actually changed the case?

I'm putting it is a new mardave v12 carbon and thought I'd get both so I have a spare just in case.

Thank you