Abstract: A method of expanding a tubular element is provided, the tubular element having a first portion to be expanded to a first inner diameter and a second portion to be expanded to a second inner diameter larger than the first inner diameter. The method comprising: a) arranging an expandable sleeve of selected wall thickness in said second tubular element portion; b) positioning an expander in the tubular element; c) operating the expander so as to expand said first tubular element portion to the first inner diameter, and operating the expander so as to expand the sleeve to an inner diameter substantially equal to the second inner diameter minus double the wall thickness of the sleeve; and d) retrieving the sleeve from the tubular element.