If it was legible and didn't use construction jargons, I could translate it easily. Korean jargons are the worst things for Korean speakers.
1층 진입기존계단 철거후 (After demolishing the conventional stair towards the 1st floor)
지층*으로 연결하는 LOADING DECK 설치 (Build a loading deck that connects to the ????)
지층계단왕**으로 건물 주현관** 설치 (Build the main entrance area** ?????***)
* I have no clue since it's a construction jargon
** Very blurry to read; don't know the exact words
*** could be an instrumentive case or a certain locative case in Korean, so there's an ambiguity.