Replacing a single only bill validator with a multi-bill

[Guest]

Hi all, this is my first refurb project on a vending machine and could use some help. Am I able to replace my maka bill validator that only takes $1 bills with another brand that can take other denominations? I understand I’d probably have to replace the coin dispenser as well. 
 

Im also looking for some resources to learn more about these older machines if anybody has suggestions.

The model is a gf19 with a part number of 4202376.