These threads will answer your questions, and others which may arise. See "How to label, change or hide buttons" for the answer to your question.

RM-AV3000/3100 NEWCOMER’S PACKAGE-WELCOME-CHECK THESE OUT (IF YOU HAVEN’T ALREADY DONE SO) AND SAVE YOURSELF SOME PROBLEMS

AVOID SYSTEM CONTROL PROBLEMS

HOW TO LABEL, CHANGE OR HIDE BUTTONS

CHANGING BATTERIES (May not apply to RM-AV3100-time will tell)

AND IF YOU HAVE A SONY RECEIVER:
CHANGING YOUR RECEIVER AND REMOTE TO AV1 (or AV2) COMMAND MODE

AND FOR RM-AV3000 OWNER’S (BUT MAY BE HELPFUL TO RM-AV3100 OWNER’S) :
REMOTE CENTRAL RM-AV3000 FORUM REVIEW

REMOTE CENTRAL RM-AV3000 QUICK PROGRAMMING GUIDE