1. Go to Library Import. Select the state (MI). Then, you have to know if the trunked system or conventional frequencies are listed in the county database or statewide (sometimes it'll be both). For Michigan, I selected Systems from the Michigan state page. Then, you select the system you wish to import. Easy here, as there is only one. Once selected, the Sites and Talkgroups buttons will become active. Now, you need to know which sites (likely NOT all of them) do you want. These are defined by geography and number of users or workload. Since I don't know Michigan systems, I would encourage you to examine the state-specific forum and the state's wiki page here in RadioReference-land. Once you know which sites, select them. Use the Back button to select the Talkgroups. Some talkgroups are very local (city/county) and others may be used statewide (mutual aid, state police). Once you choose what you want to hear (which talkgroup categories), the list of known talkgroups is populated. All of them, by default, are chosen for you. If you don't wish to listen to the animal control officers (for example), simply unselect them. Once you are satisfied with everything for that system, click on the Import Selected Channels button. Almost done.....now, choose which Scanlist you want these imported items to go to. Click Import Channels to finalize.
2. The delete option for conventional frequencies and trunked radio systems talkgroups will appear (on the right side of the screen) when you highlight the one(s) you wish to delete. You can delete individual entries, use Control to select multiples or the Shift key to select multiple entries.
This Control/Shift function works for LED configuration, etc. as well.