DTSCDS: If you get a little shot of WD-40 under them with the straw, hey will slide off easy enough. Shoot a bit under both ends, spin them and slide. Alcohol works too I am told.
Trekking bars are great, but I also enjoyed my Ritchey WCS bar ends (they are angled at about 45 degrees in, felt very natural).
http://www.auvelo.com/images/bar%20end%20xcs.jpg