is it too late to raise rent?

[Shannon Trivett]

my tenant has a yearly lease which will expire April 30th 2018. I served a notice of nonrenewal, they asked if they could stay, I said we could discuss at a later time but they should plan to move. 

I am almost certain they plan to hold over, their rent is currently below market rent so I'd like to charge more. It's my understanding that in PA a yearly lease that is not renewed would revert to MTM.

I know I probably should have included hold over langue in the original lease or on the Notice of Non-renewal but it's too late for that now so I need to determine

a. should I serve another eviction notice?

b. Can I raise potential May rent now or should I just cover that on an eviction letter. 

Would an eviction have to be hung on their door or can I handle it via postal mail, texts and conversation?