Yes you may download latest Gufiak fw for your player, with English menu, form
HERE
I'm not sure what fonts are used in this fw. IF it is not CP1250, you may have problems to read subtitles with Slovenian characters.
But you may open this fw with MTKRemaker, save English Language part and then open fw form our download in MTKRemaker and replace Polish for previously saved English.
It is easy.