The easiest way is to take it to an upholsterer to have them reattach it.
Headliners can be a real pain to deal with if you don't know what you are doing. It will end up sagging if you don't do it correctly.
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"I'm not driving too fast...just flying too low"
Mine:
-87 ranger- broke
-03 SB Cobra vert- 2552 of 5082 Born 02/25/03
Our's:
90 7up vert - new project