>>1997514for a crap rattlecan job, you can put masking tape over all the parts which is time consuming but less time consuming than taking everything off and putting it back on again.
however then you have to at least sand the whole surface atleast and little so the paint will absorb and stick, or else the new paint will just peel off of the smooth original paint.
MAYBE with careful masking you could preserve the decals but unless the new color exactly matches the old color, you'll see the old color between the letters and inside the O, D, etc.
you can buy new decals for some brands but most models there's not an exact match out there. you could always just choose new decals that you like better , rather than what the bike came with. scam artists will do this to sell a crap frame as a nice Specialized etc.
it'll look like shit compared to a factory or pro repaint, but you get a color you like. clear coat after. put any new decals on before clear.
doing it the real way involves stripping all the parts off (which will require a few special tools) and either chemical strip/sandblast/hella sanding to strip the old paint, prime, sand, prime, paint, sand, x2, clear. pros use a paint sprayer not rattlecan. but then you have a huge chore of not just reassembling the bike, but also tuning both brakes and derailleurs. and getting your fit back perfect.
