No mucking around with this one.
At the posted cordinates you will find a 10 digit number beginning with 13.
this will be your cypher as in 13nnnnnnnn = A B C D E F G H I J
replace the digits found for each letter with the corresponding numbers in the final waypoint code and you will have the location.
Stealth may be required at both locations
S: 33'2(I).(A) (E+F) (J+E)
E: 151'2(B).(E+I) (F) (G+A)
good luck, and enjoy.