For Mario64 most will probably tell you to go look at the source code and recompile that these days. That will sort many things out almost automatically and possibly reduce any text editing efforts to it actually being harder to edit a post here.
Anyway the N64 did not have a file system (a means to have the big ROM break down into component files, think like a CD based game) so we are back to ROM level and RAM level efforts depending upon what the devs did.
ROM level is much as it sounds and is mostly finding values that count from the start of the ROM (or some fixed point) and where the text is.
RAM level will take where the ROM appears in RAM (for any console this is rarely starting at 00 and instead will be somewhere else in the main system memory, possibly even split up to allow it to do things -- see bankswitching on older consoles).
Most look immediately before or after the text in question as a lot of the times the pointers are there. Otherwise you are looking for values that correspond to locations in ROM/RAM for the text as these will tend to be the pointer.
There are further things that make pointers sometimes more annoying -- text formatting can be included in them, and the are the various ideas of how pointers can be used within programming -- above the thing where I said start at the start of the ROM and count from there is standard pointers, offset pointers is when you start somewhere else (usually the start of the text section) and you have relative (adding the value of the pointer to the current location is sometimes done for various programming related reasons).
You might also find something in http://www.romhacking.net/?page=utilities&category=&platform=&game=847&author=&os=&level=&perpage=20&title=&desc=&utilsearch=Gohttps://hack64.net/wiki/doku.php?id=super_mario_64:ram_memory_map
might do something more but I am not seeing things for text.