a battery holder is not a bad idea, batteries are sometimes hard to solder, even if your a self proclaimed expert (like me) and once heat starts to actually soak into the battery there is a slight risk of leakage, or rupture (or violent rupture) due to overheating

any way you decide to go you should get some old junk boards from a pc, alarm clock, vcr, whatever and practice a BUNCH before screwing up a logic board. There is technique and timing involved for electronic devices that you will learn pretty quickly fooling around.

also you need to see if you have the right gear, a 4$ solder sucker and-or some solder wick/braid is neccacary to do it right, I would also suggest tweezers and a pair of needle nose pliers