How do you convert an m1 carbine to an m2 carbine?

To convert an M1 Carbine to an M2 Carbine, you need to replace the standard trigger housing with one designed for selective fire, which includes a new trigger mechanism allowing for both semi-automatic and fully automatic fire. Additionally, you will need to install a new bolt and a different operating slide that accommodates the full-auto function. It's important to note that modifying firearms can be subject to legal restrictions, so always check local laws and regulations before proceeding with such conversions.