Filing a dykes ringset isn't generally done. Even if the gap is widened, there is the locating pin to consider.
Not that it can't be done.
Why Wiseco? They have only one size of piston. A Pro-X will come in the multiple alpha designates that indicate different sizes. Yeah..only 1/2 of one thousandth from one size to the other, but it does give you the chance to pretty much custom fit to any situation.
'General lubrication'??
I'm not sure what that means. There are lubrication points on re-assy for sure. The piston should immersed (or as good as) in 2-stroke oil. You definitely want the rings/lands and skirt lubricated. Same for the wrist pin and small end bearing.
The subport drums and a couple of other KIPS points should be lubricated also. Those points are listed in your manual.
Make sure the KIPS works as it should after the head is bolted on (18ft/lb-216"/lb as I recall btw).
If you don't lubricate it as indicated, it might not (work) as it should. ANY binding in that area MUST be resolved.
Oh...and 'resolution' doesn't mean loosening the head nuts, either!
As noted in EG's write-up, be sure to guide the rings past the intake port (via access THRU the intake port) on assy. They can snag.
Actually, there's a whole lotta stuff to take into consideration...like being sure you protect the crankcase (cover with clean rags) on assy as you don't want to be fishing a pin clip out of that cavity after it goes s-p-r-o-i-n-g someplace.
Oh..and if it's a Seizeco..I mean WISEco...make sure the clips fit into the piston groove as they should. Wiseco made some wrist pins that were a bit long preventing full seating of the clip.
Those clips have come out when running. That's not a good thing.
Look at the bright side...maybe you'll get to do it all over again (if that happens).
If you have a specific question, please ask. 'Any special instructions..' is a bit broad. Maybe this is your 11'y-second engine rebuild..maybe not.