That Philips scope is very much a push together plastic housing, take care when pushing tabs to get it released as the plastic hardens with age and easily breaks. I had mine apart some years ago and the specifics are a bit hazy, but the attached photo is the rear of the front panel and it looks like the 2 screws hold that on and I suspect the BNC connectors are behind that and they should be held on with a nuts. The open area is where the internal battery would go, which I presume your unit doesn't have. Alan.