You have to be from New England or old England to pronounce it correctly.
Take the word "wuss" add "stah" and then "sure" and you approximate the correct pronunciation. Subtract "sure" and you get the pronunciation of Worcester. It's not Wooster (that's in Ohio), Worchester, Worsester, or any other way.
Once you master Worcester, try Leicester and Alnwick.
Leominster is another.
I think I know Leicester; and Wiki is my friend:
https://en.wikipedia.org/wiki/File:En-uk-Alnwick.ogg
you should hear how city’s are pronounced in Tx LOL