Pulling the battery wont reset the OLM, there are 3 ways to reset it.
1) With the key in the ON position, pump the gas pedal 3x. The Change Engine Oil light will flash 3 times and reset the OLM to 100%.
2) If you have a DIC, you can browse to the OLM and it will tell you the current status. Hold the Enter button (DIC button with the arrow) for ~5 sec, the Change Engine Oil light will flash and the OLM will reset to 100%.
3) Use a high end scantool such as EFILive, HPTuners, Tech II, Snap On Solus, etc you can manually reset the OLM. Each has their own way of doing it so I cant comment on any except EFILive. With EFILive (and I imagine HPTuners), you can program any OLM status you want from 0-100%. Makes it handy if you accidently reset the OLM (ask me how many times Ive done that, at least 5
).