like pulling teeth - extremely difficult
"Getting him to sign on the letter of agreement was like pulling teeth."
How about using multiple idioms in one sentence?
Here is my first attempt -
Additional idioms needed to make the sentence:
twist somone's arm - put pressure on someone to try to make them do what you want them to do
spill the beans - to let secret information become known
"The interrogator pulled his teeth out in order to twist his arm into
spilling the beans."