Hello. Instructions on how to remove a soap dispenser drawer for cleaning are usually in the instruction manual. If you don't have it you may be able to download one from here washing machine instruction manuals
That's assuming it is meant to come out, but most should be. At the end of the day it shouldn't be difficult, there's just something at the back (possibly underneath the drawer) that stops it coming all the way out and a tab or device to press to allow it to come out. Some are even cruder that that and just need gently prising out.