Originally Posted by Paul_M

Success!

Thank you all for your advice. In the end I followed the advice to inflate using an inner tube first, then to take off one side. I also bought an air tank (tire booster) to ensure a rapid inrush of air under pressure, which seemed to work well. I managed to seat the tire on the second attempt. I then went on to put the sealant in by removing the valve core and using a syringe.

Thanks again for all the suggestions!

Best regards,
Paul