What kind of personal guarantee?

Is it a good guy guarantee? If it is, then you just need to be current on all rent payment and give landlord the advance notice as the lease proscribed and you will be off the hook personally. Of course, I assume that you don't have any meaningful assets in your company, right? So you don't really care whether he sues your company. If it is a full personal guarantee, you need to have an experienced lawyer to negotiate with the landlord. And I will never recommend paying rents up-to-date under such circumstance. Since you would be the breaching party, what you need to is to put landlord into a fear that he would lose much more if he does not let you go free of liability. An experienced lawyer will help you achieve that. However, if you pay all the rents up-to-date, landlord has nothing to fear and will never relent. In business negotiation, it is more about money than law. So you really need to play into the other's head and only use laws and contracts if it is your friend. Never tie your hands with laws, remember.