Just use the edit button
On-Topic:
The save file are located on the subfolder "saves" on project64 folder. It should be named as the internal rom name. To know which is the internal name, right click the rom you want to know, then click "Rom information". A new window will appear, the first line it's the rom's name. The extension might change from one game to other, depending it uses battery sram, eeprom, etc. Ocarina of time should be a .rsa file.
In my particular case it's named "THE LEGEND OF ZELDA.sra"