I let a dryer sheet get sucked into the lent trap amazingly and it has begun to make a strange noise since when running. Question is how do I access the inside of the trap in order to get the sheet out?

If the lint screen is on the front under the door of the dryer, you will need to remove the front panel to access the lint channel under the drum, from there you can clean out any lint that is built up under there, as well as the blower wheel, to provide quiet, smooth operation.