how can I remove setup tasks?

In QuickBooks Online SETUP TASKS page, there isn't a way to remove an item itself such as the 401k. However,  you can complete it so it won't show as part of the pending task, Lisa.

If you do not want to proceed with setting up the 401(k), you can click the I'm already covered link at the bottom. See the screenshot below:

It will then show as completed with a check mark.

Don't hesitate to comment below if you have questions about SETUP TASKS page in QuickBooks Online.