How to update Firmware/Software on Motorola MG7700

I’ve been looking online everywhere and I can’t figure out how to update my firmware or software if it is even possible. I read somewhere my internet provider updates it (Xfinity) but I don’t know how to tell if they’ve done that. I feel like recently my internet hasn’t been performing as well and I just want to make sure I’ve done everything I can to keep it speedy quick. 
current firmware is V1.0

software 7700-5.7.1.21