Mom pulled cable need help!

so ill just skip to the point my mom ripped the cable out of the mouse, and i can see 3 out 4 of the raw cables out and a bit of the 4th hiding inside the plastic so i need help with how to fix it or i mostly need help on how to open it. I can solder the cables but i just need help on opening the rest of the mouse without breaking it. (my warranty expired so i cant replace it)