As DrWebster has mentioned, your first mistake is to put RJ45 ends on the wires. You should be terminating to modular keystones. Mount those in a nice wall plate screwed onto a low voltage wire ...

Assuming those 3 CAT5 runs each only go to a single wall jack (and they are not daisy chained together) you can simply replace the RJ11 with RJ45 (keystone most likely), punch down all 8 wires ...