The screw with which you tighten the lever to the bars - yes, just get a bigger screw and re-thread the exsisting thread. The long screw with which you screw the lever to the "body" or whatever you call it - just get a longer screw and do it up with a nut, but make sure that the part of the screw which the lever pivots on doesn't have a thread. Hope I made myself understood, my english is very poor in these matters