HI Michael
The easy solution to showing the property to multiple buyers is to have a 1 or 2 hour open house. Have everyone show up at the same time, including the seller if she/he insists on being there.
You might offer the tenants a $20 couple for a local taco or pizza place to get them out of the house. You really don’t want them to be there.
Hopefully, you have been truthful with the seller by telling them that you are not buying the house but you do have a team of potential buyers who want to see the property.
The problem with having the seller there is the buyers could very well go direct and try to cut you out of the deal. You can avoid this by making sure the buyers know you have a contract.