If you didn't think my previous post was constructive enough then just give it a go with some ear plugs and whack anything that makes a noise with a lump hammer...
You don't mention what system you have and even so they are all different depending on the system design.
May need ladders to reach the outside box, you may not if SAB is inside. Either way you will not do it silently if the system works properly.
There are no grade 4 IAS panels on the commercial off the shelf market in the UK.
Grade 4 is only available to Government/Military who need an additional level of security.
There are very few (like 2) grade 4 detectors - also not available as COTs
Assume it is for signalling only or ask for a Threat and Risk Assessment that informs a G4 solution.