1. When you have icon created rescale it to 64x64 and copy to ---> flight\TEWS.
2. Check and add radar entry in list file. --> cockpit\RWR_IP-1310\IP-1310_RWR.LST
3. Publish your new IP-1310_RWR.LST and your new symbol in comments, pls ;-) ...
C A U T I O N
Ofc if you want have all these symbols on your RWR you MUST rework radar entries in your planes and ground objects.
Well .. life is brutal ;-)