How to negotiate inherited tenants with seller

I have just put my first property under contract this morning. I owe a huge thanks to BP and all its members especially @brandonturner and @davidgreene definitely couldn’t have done it without you guys. So now I’m going through the inspection time and I kinda got screwed on their counteroffer cause they accepted my price (299,000 on a 5br/2bth 3000sqft In Portland, OR) but they wanted to cut my inspection time in half from 10 to 5 days. I knew I would be pressed for time but I did it anyway. So my question is about the current tenants in the house their are five people currently renting rooms for various prices depending on room size. I kinda want these people to stay as long as everything checks out with their background check and credit report. So in Portland they have very strict renters laws favoring the tenants and it can be very expensive to get them out of a residence and what I’m wondering is how to negotiate that to my benefit with this seller. Any comments or tips would be greatly appreciated!!! Thanks everybody