Billymueller's advice sounds good. I didn't know that so just pulled the panel loose at the bottom and sides, enough to slide my hand behind with the little "speed nuts" on the tip of a finger and used feel to find the posts on the speaker grille then pushed them on one at a time. I used a little sticky glue to hold the nuts onto the tip of my finger. It worked but my wrist got scratched some.
Good luck.
Ray