I am trying to replace the faucet in my kitchen. Circa 1960 something. The water line in is 1/2 inch copper w/ a threaded end, then a brass coupler that takes it from half inch to quarter inch. I'd like to remove that threaded coupler but I can't seem to break it loose. Any suggestions would be appreciated. Thanks for your help,
Christie
Ps space is quite tight so longer levers are not an option

Have you tried heating the connection? If the threads show any evidence of water leakage, the connection may be seized to the point that the male adapter would have to be cut off the copper line and replaced. Good luck.

A basin wrench is used by most of us in this tight spot. You can get them at ACE for about $7. https://www.hardwareworld.com/11in-Basin-Wrench-pN7NTI2.aspx