Old Tenants Lock Doors - Unable to Show Rooms

[Matce]

My question involves landlord-tenant law in the State of: CA

Two short questions here:
I had to give a 3-day notice because of non-payment of rent and Im having major issues with the tenants being immature and trying to complicate thing as much as possible. I am renting a house and subleasing to them (landlord is fine with this).

Can they legally lock their doors, making it unable for me to show the rooms to new future tenants? If I remember correctly I have to give them a 24h notice (verbally) that I will show the room to someone and they have to comply? ... or else what?

Also two tenants are trying to "blackmail" me to retract the 3-day notice (made up accusations) - wouldn't that constitute "nuisance" and also an unlawful act, justifying a second (non-fixable) 3-day-notice?

thanks

[Mr. Knowitall]

Can they legally lock their doors, making it unable for me to show the rooms to new future tenants? If I remember correctly I have to give them a 24h notice (verbally) that I will show the room to someone and they have to comply? ... or else what?

Read this - scroll down to "When can the landlord enter the rental unit."

Why don't you, as their landlord, have keys to all doorknobs? Does your landlord have keys he can provide to you?

You're already in the process of evicting them. There's not really a stronger measure you can take than eviction.

Also two tenants are trying to "blackmail" me to retract the 3-day notice (made up accusations) - wouldn't that constitute "nuisance" and also an unlawful act, justifying a second (non-fixable) 3-day-notice?

From what you've told us so far? No. I doubt that the threat to accuse you of something would give you grounds to evict as a "nuisance" no matter what the facts, but you can review the actual facts with a lawyer to determine your rights.