Mares Arturo 6v - question

[pantapita]

Hi there,

I bought one lamp - Mares Arturo 6v in a diving center that was closing their bussiness down. Need not to say it was way too cheap to hesitate, so I risked...
So far it worked fine for a few weeks and I'm happy with this lamp. But two days ago bulb went off and now I want to change it. As I don't have any more contact with guys I bought Arturo from (they went for Italy) and don't know anyone who owns Arturo, I ask here: HOW THE HECK ONE CHANGE A BULB IN ARTURO???

By Googling, I just found that Arturos come with three bulbs (20W, 50W and 100W) and it's perfectly normal thing for user to change bulbs...
BUT HOW?

I figured it must be some twist or unscrewing or something with big top plastic ring that holds glass protecting bulb from water..

i'd appreciate any help

thanks

 

[pantapita]

Problem is solved... One nice guy sent me scanned manual for the lamp.. Thanks Damir..

The plastic ring has just jammed, need more force.