Depending on the dent, you may not need a cue repair person with steam or a lathe. Try this first:
• Take the corner of a small piece of sandpaper and lightly rough-up just the dent -- just kind of removing anything sealing the wood.
• Place the shaft flat on a table, cabinet, floor, or whatever -- with the dent facing up.
• Place one drop of water in the dent.
• Check it after a while (10 min. or more or less, not critical) to see if the dent has risen at all.
• Repeat, if necessary. This has worked for me many times. You can burnish the shaft afterwards.
• Resort to one of the more involved methods if the simple drop-of-water approach has failed.