Need advice on cutting entry door through existing exterior stone.

So this structure is a 2x4 framed garage with a loft. There is a full size natural stone exterior facade with about a 1 1/2 inch air gap between the stone and the wood framing.

How would one go about cutting a new entry door as shown in the photo? I'm wondering about the sequence/details to achieve this safely. Lintel required? If so, what would be the easiest method/materials (including fasteners/mortar/adhesives) to use for retrofitting the lintel. Thanks 👍

So this structure is a 2x4 framed garage with a loft. There is a full size natural stone exterior facade with about a 1 1/2 inch air gap between the stone and the wood framing.

How would one go about cutting a new entry door as shown in the photo? I'm wondering about the sequence/details to achieve this safely. Lintel required? If so, what would be the easiest method/materials (including fasteners/mortar/adhesives) to use for retrofitting the lintel. Thanks 👍