>>6010730R-1134 surveys his surroundings. Behind him, near the stairs lies an elevator, its doors lying ajar and clearly broken by the either the warfare or the failure to maintain. R-1134 looks down the shaft and, although it would difficult to maneuver into, he can see a small maintenance tunnel, most likely used by the many children of the Imperium, or its rebel leaders, to scurry around and fix things only their little hands can reach. R-1134 is fairly certain that he would be able to get to his destination from that tunnel. However, the drop down the elevator would certainly kill him if he screwed up his acrobatics.
To his right lies an orange door marked with the symbols of the maintenance caste - Two crossed brooms and a bucket. Opening it, R-1134 can see a crack in the wall leading to the bunker pillbox. He is fairly certain that using his entrenching tool, and some force, he will be able to clear the wall effectively enough for him to bring his lasgun to bear. Hes not entirely certain, however, if that would draw the attention of the soldiers using the multilaser.
Finally, R-1134 considers the armoury on the ground floor. Although heavily guarded, maybe the distraction of the klaxon and general war, he might be able to fool the Armourer and his staff. High risk, high reward