Open the brown "omnibox" and take a look - good chance that the incoming cable is connected by an in-line F-type connector that's secured by a nut. In that case, undo it carefully and you've got a free cable to work with, that can easily be reconnected, although minimise the time it's disconnected as there's a risk of noise ingress through uncapped cable ends. Make sure the builders understand the important of not damaging, crushing or crimping the cable (eg by too tight a bend).
If the cable is captive in any way, then the £25 non-fault call out beats trying to sort it out yourself.