Contrarian,
you dont have to replace the cranks entirely, if you just want new chainrings.
buy the 3 chainrings, actually just get the bigger 2..
i use a 50,40, 24 triple, have for 20 years..
i wouldnt want to raise the low gear.
BB might be worn , , seek bike shop help , for direct replacement..
I have a 97 Jamis Aurora with an RSX 3 x 7 drive train. I want to gradually rebuild the entire drive train. I want to start with the crank set which is now 46/36/26. I want to go to a 50/39/30. Problem is, I can't get the crank bolts off to see if the spindle is square or another type. The BB seems fine. I have the correct size allen key, but I don't think it is torquey enough. Any help will be apprciated.
I'd bring the bike to the Shop and let them have a look.
since I cannot see what your wear and tear condition of stuff is over a website.