Ok, on your old esc hold the black plastic plugs TIGHTLY and give the wires a hard pull. The copper contacts will pull out of the plugs. Unsolder them and solder them to your new esc then stick them back into the black plug.
Just be SURE you have the polarities correct.
Also be sure you have a GOOD solder joint!!! the monster pulls a Lot of amps.

Reptile DHP ecm, ported SC, ported and blocked LIM, SD headers, 1.9 Harland sharp rockers, HAI