Just sussed it after trying these posts - you need a large pair of pliers and insert the simple spring section into the allocated slots and griping hard, you twist until the raised groove moves into the wider section(easily identified) and then push hard until it locates flush with the lid. Make sure the slot at the end ( the part that locates into the lid mount) runs parallel with the lid as this will ensure the lid is held upright when it is mounted on the cooker. Hope this helps :-)
Dave
December 2009