Could you guys remove the previous owners Apple ID on an Apple Watch Series 3

 you need to be able to contact the previous owner to have them log out of iCloud or go to https://www.icloud.com/find/ My Phone and erase the device, then remove it from their account. If you can’t do that, the device is useless. Apple won't unlock it.

Turn off Activation Lock - Apple Support.      

See Turn off Activation Lock https://support.apple.com/en-us/HT201441and 

About Activation Lock on your Apple Watch https://support.apple.com/en-us/HT205009. If you can't turn the activation lock off using the instructions given in the link and want to make it functional, you'll need to get help from the legal owner. Doing so undoubtedly won't be possible. And, even if it is possible, the legal owner is not going to help anyone use a watch that most lkely was stolen form them.

If you want to contact Apple support to discuss your problem, then use the support options below. Alternatively, if an Apple Store is open in your area, then you can go there to deal with your problem. In this case, you can make a genius-bar appointment (https://www.apple.com/retail/geniusbar/) if you want.

Get a call from Apple support to help solve your problem using this link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

Apple ID Support https://support.apple.com/apple-id

Apple Support Twitter https://twitter.com/AppleSupport

Apple ID account security for country-specific and region-specific help https://support.apple.com/en-us/HT204169

Get Support: We’re here to help  https://getsupport.apple.com/. Go through the options to find the best support option.