Lenovo Legion 5 Pro Disassembly (RAM, M.2 SSD upgrade options)
Lenovo Legion 5 Pro 16ACH6H Left SSD Replacement - iFixit Repair Guide
Lenovo Legion 5 RAM & SSD Upgrade - YouTube
Lenovo Legion 5 15IAH7H Gaming Laptop Core i7-12700H 16GB RAM 512GB SSD 15.6" QHD NVIDIA GeForce RTX 3070 Ti 8GB Graphics Win 11 Home - 82RB000XUK | LaptopOutlet, UK
Yes, Legion 5 Pro has two NVMe PCIe 3.0 2280 SSD slots, the second slot is empty and has a pre-installed heatsink with a thermal pad. (I installed Samsung 970 Evo 1TB