What kind of bike?
The swing arm pivot bolt could be a challenge w/o an impact, and also may be inverted, ie hex, requring an allen (like on a 954).
As far as the chain, the master link can be removed/destroyed, and then replaced w/ a new master when reassembling. If the chain is in good condition, no need to replace it.
As far as wheel alignment, modern bikes come with spacers from the factory, so outside of putting it back like you found it the spacing is not adjustable.
on Chain slack, I like 3/4" up to down, and a freely spinning rim. Its an eyeball thing.
Look over all the fastners to prepare, and then approach the swap, don't start it w/o all the tools avail or you'll be pissed fast.
Also I assume you have some means to support the frame while you remove the swingarm? I'd sugest ratchet/pulley/chain setup to the roof/rafters or something similar or secure. An engine puller works well for this too, thats what I use when doing extreme disassembly on a bike.
"Jesus has my heart, but Whiskey has my liver" --Jason Boland