Get yourself one of those G5 sharpening tools!
I can get them sharp with a file,stones and strop but it's slow and it took a long time to figure it all out. I have one of the 3Rivers tools that are like this but can't get these results with it. I haven't tried their new one that is made for 3 blade heads yet though, it might work just as well.
I bought one these G5 tools in the classifieds here and finally got around to using it. I can shave with it right out of the tool, give it 2-3 strokes each side on a polishing stone and 1/2 dozen on a strop on they pop hairs.
Way faster and easier than my other methods.
The secret still is very very light strokes after you have done a few heavy ones.