How to get contractor bids for an occupied property

[Solace Medina]

I just closed on a 4plex that has all the units occupied. The tenants are on month to month leases so 30 day notices are going out. The plan is to rehab all the units at once when the property is vacant. The problem I'm trying to solve is how do I go about getting contractor bids for the work with the tenants still living there? I want to avoid the awkward, weird situation of walking multiple contractors through each unit and discussing the changes I want to make while the tenants are present. As you can imagine, the tenants won't be thrilled to receive the 30 day notices and I can foresee issues with access into the units. I would like to be able to gather bids ASAP so that rehab can start right when the tenants vacate. Has anyone found a great solution to this?! Thanks in advance!!