I was once daft enough to say that my bike had had its stock plastic fuel tank replaced with a steel one. They wanted another thousand quid!
Make/use an A frame (engine hoist) to tie up subframe when removing rear swinger or put car jack/block of something under engine. Simples. Some bike lift stands like ABBA etc can lift whole bike up too.
I used a trolley jack and had the son hold it while I pulled the swingarm out and dropped in the other one
footpegs out and flip them upside down so they don't flip up. then just use axle stands underneath them, more than capable of taking the weight of the bike.