Here's one way to do it!
Just copy the whole block below (change names to match your table) and run it in the SQL window.
UPDATE table SET field = replace(field,"0","");
UPDATE table SET field = replace(field,"1","");
UPDATE table SET field = replace(field,"2","");
UPDATE table SET field = replace(field,"3","");
UPDATE table SET field = replace(field,"4","");
UPDATE table SET field = replace(field,"5","");
UPDATE table SET field = replace(field,"6","");
UPDATE table SET field = replace(field,"7","");
UPDATE table SET field = replace(field,"8","");
UPDATE table SET field = replace(field,"9","");