some SRAM chainrings are drilled already in two different places for the chain peg, 180 degrees apart. In the ones I have seen the peg is lightly riveted in place. If so, it can be as easy as knocking the peg out (eg using a drift and a small socket to support the chainring close to the peg) and then refitting it in the other hole. A knock with a suitable punch will reflare the rivet head well enough for it to be secure.
cheers