had my speedo out recently, to put it back, rubber into cowl first with some grease, and then with what we called a hooky tool, like a screw driver but ground to a blunt point and bent to a hook shape at the end, it's what we used to fit windscreens with, push the speedo into the rubber keep pressure on it and slowly with the hook tool inserted into the rubber move it round lifting the rubber onto the bezel. Hope this makes sense and is of help. Cheers Ian.