Question

2) I was trying to figure out how we should go about it.(
(Place the modal auxiliary with another showing obligation)​

Answer 1

I was trying to figure out how we must go about it .

Hope this answer helps you friend ♥️

Answer 2

I was trying to figure out how we must go about it.

• Modal verbs are auxiliary verbs that are used to indicate the possibility, ability, permission, suggestion, obligations, orders and requests.
• Should is a modal verb that indicates suggestions, permission, obligation, recommendation, etc.
• Must is a modal verb that indicates orders, necessity, firm obligation, orders, etc.

In the above-mentioned sentence, the modal verb 'should' is changed to another modal verb 'must'.