You don't actually require the tool because the timing chain comes with coloured links (two purple, one blue) so as long as you have the engine at TDC with the camshaft lobes of No. 4 cylinder at 10 o'clock (inlet) and 2 o'clock (exhaust) you can proceed to remove and install the chains.
@[deleted] is the guru for doing the chains but unfortunately he is a fair distance from you (I see you're in Scotland). I believe @[deleted] is in Glasgow so he could be a possible option.
🙂