By coincidence I've found on Youtube a short video on how to raise the linkage arms on a Fergie TE20, without the engine running, by waggling the PTO shaft back and forth using a spanner - it's by 'ploughmyfield' and titled 'Raise an Implement' - might be worth a search for it and see if the same technique would apply to your tractor. Must admit I haven't tried it yet on my Fergie but I've filed it away for future reference, just in case.