Method for removal of food in impacted cheek?

[PurpleKat]

My 2 year old dwarf hamster, has an impacted cheek.
She's gotten elderly and I think she just can't get it out.
I understand you gently massage the base of cheeks, but what's the best method.

It doesn't seem too impacted, mostly small seeds, but I think it's affecting her eating as she's lost weight, from 45g to 35g over a month.

I was looking for a clear video if anyone has any tips?

I would take her to the vet but at her age I'd worry about the stress.

I'm monitoring her carefully, and switching her to half her regular diet and other half to pureed food. Her poops seem dry.
Also, she is still running on her wheel in little bits so she's going strong, despite her weight loss and age.