Don't think anyone actually knows how they strung their warbows in medieval times, there will doubtless be plenty of people only too keen to offer their opinion though!
Del
Everyone credible knows they used short guys to string the bows. The archer held the bow parallel to the ground and a guy on each end would grab a hold of the tip. When the archer lifted, the combined weight of the two shorties would begin to bend the warbow. The one on the upper limb would let go with one hand and slide up the loop to the proper position in the nock and shout, "Strung, you daft bugger, lemme down NOW!"
I have references here somewhere...
Meanwhile I am gonna go watch the videos again. Turned out pretty nice, as usual, Mr. H. Cheers!