Not sure how far you have got, can you start the bike?
Regarding the coils, first thing to check is do you get a spark at the plugs - with them removed from the cylinder head but held against the engine to earth? May be difficulty if you can use the kick or electric starter, so you need to get one or other sorted first.
I had a coil problem for a very long time. I eventually decided to swap the HT leads between cylinders (you also need to swap the leads that control when each coil fires). In doing so the lead on one side cracked. If it was not the problem before it was now. So I replaced both coils (hard to find, but CB500 twin ones worked).
The best advise I can give you is get or download, a shop manual.
The CB/CL/SL 350's are pretty mush straight forward.
With the manual you can do everything yourself.
