A method of assembling of a stent graft (20) including temporarily diameter reduction arrangements to enable partial release of a stent graft to assist with positioning before complete release. The diameter reduction arrangement includes a release wire (72) and flexible threads (74, 80) extending to struts (76) of a self expanding stent (70) either side of the release wire and being pulled tight. Removal of the release wire enables full expansion of the self expanding stent.
