Round trip of Tateyama Kurobe Alpine

If I have hotel in Toyama, how can I go roundtrip on the Tateyama Kurobe Alpine route? Please explain what it is and how does it operate.

Yes, it is possible. You just have to buy tickets for the route traveled. For example, if you travel from Toyama to Murodo and back to Toyama, you should buy a round trip ticket between Toyama and Murodo. Or if you go as far as Kurobe Dam, then you should buy a round trip ticket to the dam and back.

More details are explained here:
https://www.japan-guide.com/e/e7551.html#section_orientation

And tickets can be purchased online here:
https://tateyama-kurobe-webservice.jp/AlpenTour/html/VW001W0010.html

Thank you for the information. We are not planning to visit until November. I am still a little confused about the process.
1. We need a round trip train ticket from Toyama to Where?
2. We need a round trip ticket from Where? to the end of the Alpine line.
3. How far in advance can we purchase tickets?
4. Do we need exact times, or just dates?

Thank you

1. We need a round trip train ticket from Toyama to Where?

It is up to you. As far as you want to go. Also, you don't NEED a round trip ticket. You could also buy one way tickets

3. How far in advance can we purchase tickets?

From about one month (currently you can reserve through May 20). But you could also buy them on the day of travel at the station.

4. Do we need exact times, or just dates?

Dates. And just for the Tateyama Cable Car you also need to specify a time. You can go without time reservation, but on busy days it may mean that you have to wait for a long time because people with resrevations are given preference.