From the Excelsior: The Excelsior Hotel is offering a shuttle service to the conference centre MCC from Tuesday 18th, May to Saturday 22nd, May.
The Valletta circular bus service is also available and passes from near the Excelsior and stops by the MCC every 30 mins from 6:30 am to 6pm (Bus no. 98 or 198).
From all other areas: All towns and villages are serviced by buses to Valletta, which is the main bus terminus in Malta.
Walking from the main terminus to the MCC is rather straight forward: Go through the city gate and walk straight down all Republic Street (downhill! Takes approximately 15 mins). At the end turn right and you will see the MCC with the LREC banner outside.
A Google map shows the path - http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=109271279696329129988.00048677f0da12448f69a&ll=35.897829,14.513304&spn=0.012202,0.01929&z=16