REF ZENCART VERSION 1.3.8a -TO UPGRADE TO NEWER VERSION - HELP

Hi There The guy who set up our web about 3 to 4 years ago has emigrated When he set up he had done some customisations And we are currently running version 1.3.8a However to update to the newer version -I think its 1.5.4 - some stuff needs to be amended etc - of which unfortunately We are not aware of how to go about Is there any chance you can guide us to a person or persons who can do that for us - for a fee of course As the person has to be conversant with Zen cart We are based in the UK as per below address Your help on this issue would be highy appreciated Hoping to hear from you soon Kind Regards Harry Hargun Ltd, Unit 2 Curo Park Park St, Frogmore , St Albans Hertfordshire , AL2 2DD 017 2787 7990 (press option 1 for sales) sales@hargun.net www.hargun.net<http://www.hargun.net/>