Too Short CAT5e in Wall - eviltoast

My home was built in 2004. The Home Depot parking lot expert who wired these outlets put in a 2-outlet plate, one with 2 wires and another with 4 wires. I recently upgraded to 250mb and this outlet no longer worked. Rewiring to 568B on both ends of this cable, which is likely stapled to a stud behind the drywall. You can see there’s only a few inches available and I don’t think there is enough slack in what’s left of the cable to terminate with an RJ45 (at least with my rudimentary skills). How would I splice more wire to the end so I can terminate?

https://preview.redd.it/rpp9i4dz2r2c1.jpg?width=4080&format=pjpg&auto=webp&s=c6be3e046e3907408eebfd21b19a25e40ac692e4