I just finished blind betrayal for the BoS. I did not kill Danse and persuaded Maxson not to either. I want to end with the minutemen but I built the teleporter with the BoS. I also gave them the holotape. I need to know how I can end with the minutemen.

You can also do a secondary tape mission with the Railroad. I'm not sure how much further you would need to take their storyline or if you would need to take it further at all. I was up to date on the Railroad missions when going for the Minutemen ending and blew the "Underground Undercover" mission of the Railroad in order to work for the Minutemen. Blowing "Underground Undercover" cancels that quest and launches a new one, so at most you would also need that quest active, though it probably is unnecessary. I don't even remember if it's possible not to have it at this point.

Anyways, after you blow your cover by making the Institute angry however you like, you can talk to the Desdemona. She says the chance was blown to infiltrate the Institute with the Railroad since they don't have enough forces. You need an army. That's where the Minutemen come in. Since the RR has another tape, they give you access to it. Then you just follow the quest line from there.

Alternatively, you might be able to just pickpocket a network scanner off of Proctor Ingram. I remember seeing it on her corpse if you kill her. If that doesn't work, the above definitely works. There could also be some plot hole or some workaround where the tape doesn't even matter, and you don't need to talk to the Railroad. The Minutemen could probably just ask you to make a new tape. But the above was what I personally did.

I never involved the Railroad.

Yeah, edited my post right after I made it to reflect that that could be a possibility.

Thank you so much. I will try this and see if it works. So basically shoot and Institute scientist or synth and talk to des. And she will ask if I want to end the institute and then ask for an army then the minutemen ending is available? Can you tell me the name of the mission where the minutemen become involved again?

I've finished underground undercover for des. Does that matter?

Why post spoilers when the header clearly says DO NOT POST SPOILERS IN THIS BOARD!

The first playthrough I did I joined The Institute. But this time I want to stay in both The Minutemen and The Brotherhood of Steel's good graces. Besides, The Institute is so pretentious and self-righteous, despite their misdeeds. It was interesting to see all that high tech, but their personality is lacking. I just hope I can make it work with The Minutemen and The Brotherhood of Steel without them going at each other's throats.

You can do whatever you want and the Minutemen bow to you

They don't conflict with other factions except the tiny ordeal with the Institute.