Enter by the rusted grate

From Torg Adventure

You loiter near the grate trying to look busy without doing anything. When no one is looking, you work on loosening the grate. Some of the time you just stand there and kick at with your boots. It takes over an hour of work, but you manage to get one of the bars dislodged from the bottom of the grate. Bending it to the side, there is just barely enough room for you to squeeze through. Picking your opportunity, you slide through when no one is looking. The fit is very tight, and you end up scraping yourself on the way in, but nothing too terrible.