Hi Tpm00001,
Go to iCloud.com using your safari browser and login and then click on photos. On the top bar click on "select photos" within the "moments" section and then choose which photos you want to download to your computer. You can click on each one individually or you can hover over with the cursor on the time and to the far right of that bar the option "Select moment" will be highlighted.
If you go to "albums" section, you will need to click on each one individually, this is a long process if you have too many pics or videos to select (as there is no select all option).
After the selection process, the top bar will turn blue, on the left top corner" will indicate how many pics or videos are selected and then in the middle just choose "download". The selected pics and videos will download to your "downloads" folder, which you can open through finder.
After the download has ended then you go through the select process again then you will press on "delete" within the blue bar to trash them from iCloud.