How to get access to the secret room in Bossbattles wad?

Hello;
In Bossbattles.wad,"the museum" that allows you to have monsters fighting each other, there is a secret room that has the giant bosses, can someone tell me how can i reach it, because the door is blocked.

the wad doesn't work at least for me.

EDIT: Works in GZDoom but not zandronum 1.2.2.

Uhhh...

What is idclip?

Crasger said:

Uhhh...

What is idclip?

i think he wants to find the non-cheating method.

Pure Hellspawn said:

i think he wants to find the non-cheating method.

idspispopd?

Yes, the non-cheating method, like a hidden switch...

Try opening up the wad in something like Doombuilder! You'll be able to find the matching linedef tagging that way~

FuzzballFox said:

Try opening up the wad in something like Doombuilder! You'll be able to find the matching linedef tagging that way~

Yeah, or this method could work for 'ya.