One way that you can lubricate the speedometer cable is to disconnect it at the transfer case, pull it out, apply liberal amounts of lubricant (lithium grease? SylGlide from NAPA?) then slide it back in. The problem with this technique is that you end up rubbing off the lubricant as you install the cable - Plus, you may need to wiggle the cable a bit until it seats into the back of the speedometer.
Another method would be to remove the gage cluster, disconnect the cable, remove the cable from the transfer case end, use the cable to poke lubricant down the cable tube then re-install the speedometer cable dabbing lubricant on it as you insert it, connect it to the back of the speedometer and then re-install the gage cluster.
I don't think that you can pull the cable from the dash end because there is a fitting on the transfer case end of the cable.
For more information on gage cluster disassembly, go the the local library and check out a copy of a Chilton's service manual for the Sidekick/Geo Tracker. Haynes will also work as a poor second...
Hope that this helps!