to remove the plastic oval from the chrome surround and housing is kinda difficult, i'm not going to lie to you, some come off easy, some are a pain, believe me i've done about 8 of them
anyways its just attached by glue so you want to heat the emblem up really good with a hair dryer then quickly with the smallest flat screwdriver you have *i find that ones for repairing glasses works the best* and gently pry under the plastic oval part. go around the oval doing this trying to get as far under it as you can with out cracking it, then heat it again, and start at one end of the oval get your screwdriver under it good, and try to work just the small part either of the edges of the oval free. you should do this because if you don't you might snap it, once you've gotten a small part of the edge free, take the screw driver and put it under the plastic LONG WAYS, as if you were going to cut the emblem in HALF. Slowly shove it under wiggling it free....
i guess find what works best for you
but make sure hte emblem is heated at almost all times so the glue stays sticky