318 LA oil pressure sending switch source of oil leak

Hi I think I have found the major oil leak on my 1977 LeBaron it appears to be the oil pressure switch which appears to be unthreading from the block . How difficult is this to replace . I use about 16 ounces of oil every 250 miles and this appears to be the major leak. Any advice and guidance would be greatly appreciated.
Author: 77 LeBaron