If it doesn't open from the front, then I'm sure it should from the back. If I remember and correct me if I'm wrong this is an old Russian made watch from around the 1980's time, if so Russian watches never had any fancy way of opening back then. This is a bit of a long shot and I can't think that it's the way but I'll mention it. have you tried pulling the stem too see if it is a two piece stem, if it is you then remove the glass and the movement will drop out. If you try it be very careful as damage can be caused. By the look of your photos you are not the only one to have had this problem it looks as if it has been tried by someone with a hammer and chisel.
I expect you will have more replies from those that are still working with watches, me I retired from this type of work years ago so it is just my memory that I have, at times that's not to good.
Good luck.