If you mean the small side light it just twists then drops out.
The leads are fixed to the coils, you can trim a few mm of the end to tidy them up but you can't replace just the leads.
Misfire could be anything, so you need to do things one at a time.
Trim the HT leads if you're gonna change the caps anyway. Look on Ebay for NGK SB05F as a good and inexpensive replacement part.
Check the air filter isn't all dirtied up blocking air flow.
Make sure the fuel tap is turned properly on, and for a few quid you can get a new fuel filter and change that as well.
Do a quick test on the TPS, make sure that's in the right position and functioning okay, they make a bike a bit erratic at idle and low revs when they're on their way out.
The carbs probably need balancing too i'd imagine, but you need to make sure all of the above are okay first before going anywhere near attempting that one.
TPS check http://foc-u.co.uk/index.php/topic,13864...#msg157056
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