At the start of the mission, you’ll have to clear out the house in front of you. After clearing it, head to the second floor of the house and turn left to find the remains of the 2nd floor bathroom. The SS Pin is attached on the mirror frame on top of the sink. You’ll have to carefully jump on the broken wall to get near the memento and collect it.
Clear all enemies inside the church. When you’re ready to head to the church tower, head to the right side of the church hall first to find a crater on the floor. Jump there and look for a small hole where the memento is kept.
After surviving the bell tower collapse, you’ll have to defend your position against the counter attacking enemy forces. Before they start pushing forward, head to the right side of your defensive perimeter then grab the fuel canister behind the sandbag cover by the ruined house.