refitting roof dampers

[PhilXXJ]

ive recently fixed the hinges on my pop top roof (think that's the term.. hinges on one side elevates from the other) as the rivets broke away on 2 of them. To do this I needed to remove the 2 dampers which hold the roof up which have a fairly high compression. Is there any 'knack' or special way of compressing them (about 4") to re-install them? ive tried making a 'tool' using jubilee clips, threaded bar and some plates with no success.

[PhilXXJ]

Fixed it using mini ratchet straps after watching a chap on you tube https://www.youtube.com/watch?v=eaO5VSDZ2Ko" onclick="window.open(this.href);return false;