Replacing a heating element in oven

Hi

Looks like my lower heating element in my oven broke last week and today I wanted to take it out and replace it with new one. Stove Manufacturer is Koncar (a company from my country), I know it is maybe unknown to you, but is probably the same structure of the stove as in any other.

Heater that is broken is located below the oven and the problem is that I do not know how to get it out. I removed the back side of the stove and disconnected cables from the lower heating element. It is located inside the casing sheet metal together with an insulating material. This metal case has no screws to take it off, nor inside the oven (at the bottom).

Do you have any idea how to gain access to the lower heating element and remove it?

I snapped a few pictures to show you where and how it is installed.

http://imgur.com/l1enrQQ
http://imgur.com/Atog5Ac