How to Infiltrate Mercer's House in Skyrim

Go to the gate behind Riftweald Manor. Riftweald Manor in Riften is Mercer Frey's house. When you first fast-travel to Riften, Riftweald Manor is the fourth door on the left from the main gates. Use the following directions to get to the gate behind Riftweald Manor: Continue past Riftweald Manor until you reach the opening in the wall to the left that leads to the Temple of Mara. Enter the courtyard in front of the Temple of Mara Go through the archway to the right of the Temple that leads to the cemetery. Go through the cemetery and follow the path to the left that leads behind the temple. The first gate on your left after you pass the temple is the gate to Riftweald Manor.

Pick the lock to the manor gates. There’s a small steel gate in the back of the manor. Approach the gate and press the interact button that is displayed on the screen to enter lock-picking mode. This is an expert lock, so make sure you have plenty of lock picks. To initiate lock-picking, press E on PC, "X" on Playstation, and A on Xbox and Nintendo Switch. To pick the lock on game consoles, press left and right on the left stick to adjust the position of the lock pick. Press left or right on the right stick to turn the lock. On PC, use the mouse the adjust the position of the pock pick and press "W" to turn the lock. Once the lock pick is in the correct position and the lock is able to turn all the way, you will have successfully picked the lock.

Get Mercer's House Key from Vlad. Vlad patrols the property. If he sees you breaking in, he will attack you. If you have high enough speech skills (and you've paid off his debt from Maven Black-Briar), you can persuade him to hand over the key. If you have high enough pickpocket skills, you can sneak up behind him and steal the key. Otherwise, you can defeat him in combat and loot the key from his corpse.

Shoot down the balcony ramp. An arrow pointer can be seen on the underside of the wooden balcony, on the second floor. You can shoot it down using an arrow, or the Unrelenting Force shout.

Go up the wooden ramp. Once the ramp is down, climb the stone staircase on the left side to reach the bottom of the ramp. Climb the wooden ramp to get to the door that leads inside the house.

Enter the doorway. Now that you have the key to Mercer's house, you can use it to enter the door at the top of the wooden ramps. This leads inside the house. There you go! You’ve just infiltrated Mercer Frey’s house!