Been there, done that
I had to repower my '91 several years ago and am on an inland lake with virtually no marine expertice/support. I did have to remove the galley section to access, but as i recall this was really a very minor project, especially given the totality of the project. There are a number of wood screws to remove and then you just pull/jiggle and it frees up. You really only need to swing it out of the way, as opposed to remove it. While likely not the best option, we lacked a crane, we simply secured a come-along on the boom above the companionway, doubled the support of the topping lift using the main halyard and winched in and out the engines. It was a full morning's job with most of the afternoon to properly attach and balance etc... Not something I would want to do again, but actually not nearly as bad as i had anticipated.