delete icloud information on work mac

i have a home mac & a personal iPhone. my work mac is owned by my employer. on the work mac, i have access to contacts, calendar, reminders, safari and keychain. NO mail (i use gmail on safari for personal stuff), no photos, no iCloud drive (i use safari).

whenever i leave this employer, i'll have some time to tidy up my work mac, what's the best way to delete iCloud stuff mentioned above? i'd rather not change my iCloud password, i'd like to sign out and have everything delete from work mac.

when i click on sign out, i get a window asking if i want to keep a local copy of contacts, cal & reminder. no mention of safari and keychain. i could re-set safari easily, delete the bookmarks.