A piece of advice an old instructor gave me about shooters with weaker hands:loblolly wrote: Im able to rack the slide with quite a bit of effort but its pretty awkward and sometimes too difficult when my hands start getting tired.
Hold the slide firmly in one hand. With the gun pointed in a safe direction (the ground is easiest for this) use the hand on the grip to push the gun down while trying to hold the slide in place.
Here's a video of a woman explaining it a little better than I did (and with visuals!)
http://www.youtube.com/watch?v=kbayNc6D9HY