Sleepy

Hi, during my jazz band rehearsals there are often times when the rhythm section has to be silent while the blowers go over a section. I would like to be able to play during these times, listening to myself through headphones. There is a mute button on the back of the cabinet (Gallien-Krueger MB150S) but it is not convenient and I would like to mute the speaker using a foot switch. Can anybody suggest a piece of kit or a modification which will accomplish this? Thanks. Martin