Canon eos sticky handgrip

1. Mix dish soap and water
2. Gently pry up with your fingers the edge of the handgrip on the inside of the handlebars
3. Get some of the mixture underneath the grip and then proceed to work it around the handlebar in a twisting back and forth motion.
4. Eventually the mixture works its way through the whole thing and the whole grip should twist.
5. Keep twisting back and forth while pulling the grip towards the outside of the handlebars.
6. Eventually it will pop off.
7. Dry thoroughly and repeat on other side.

Accidentally posted as comment, not solution, IMBNH :)

I understand there isn't a manual, just a quick how-to guide. Here's some basic use info from a review
http://www.the-digital-picture.com/reviews/canon-bg-e6-battery-grip-review.aspx

The Canon BG-E6 Battery Grip is designed specifically for the Canon EOS 5D Mark II as shown above with a Canon EF 16-35mm f/2.8 L II USM Lens mounted. To get the Canon BG-E6 Battery Grip into the position shown, the LP-E6 Battery is removed from the 5D II and the battery door detaches. The BG-E6 slides up into the battery compartment and locks into place via the tripod socket screw seen on the BG-E6 just below the lens in the above image. The BG-E6 provides its own tripod adapter threads - this functionality is not lost.

The Canon BG-E6 Battery Grip holds two Canon LP-E6 Batteries that deliver double the number of shots or video time from the 5D II. Alternatively, use 6 AA batteries in the included Canon BGM-E6 Battery Magazine shown below.

Cannon lp-e6 battery fit canon eos 5d mark ii http://www.canon-digital-camera-battery.co.uk/batteries/canon-lp-e6.htm

Try wiping it with a cloth dampened either with Windex or a 50/50 mix of vinegar and water.

Try using some rubbing alcohol on it. Should be able to clean it up.

take the grips off and wrap some friction tape around the handlebars about half to three quarters the length of the grip from the end of the bars. then put the grips back on. shouldn't need more than 3 layers of tape

Try an ammonia-based cleaner..but don't get it on the plastic.

Please see this page, on Safari Books Online - an excerpt from Canon® EOS Digital Rebel XTi/400D Guide to Digital SLR Photography which describes the steps in detail.