You might want to check out this link from the Festool knowledge base. If you have the clear splinterguard the adhesive holds better to the strip. Good luck. Renewing Splinterguard
I just looked at the article. One thing that some users use is a hair dryer to heat up and softened the adhesive. If you don't have the clear guard yet, it is an improvement over the black. The adhesive stays on the strip better allowing easier repositioning, it offers better visibility, and it is harder and doesn't get chewed up as badly.
Whenever I reused the splinterguard, I would scrape off the old adhesive, wipe it with acetone and use a spray adhesive to adhere the older splinter-guard to the rail to ensure a more solid adhesion. Works well.
So far I've managed to re-use the existing adhesive strip but if I needed to spray adhesive I'd use 3M 77. It's less lumpy than 90. All things considered I'd prefer to use one of the double stick tapes that have been sufggested.
My rails have the black rubber strip and I have peeled them off and re-adhered them several times. Peeling off is usually easy. The adhesive I use is 3M ATG tape, which is a commercial two sided tape used in picture framing, etc. It is probably available online or at a frame shop. A roll of tape will last for a few strip re-do jobs. Just remember to make a "dummy" cut on some scrap to establish the cut edge on the rubber strip.