The transition for RMG included many steps. The first step was ensuring that Python 3 versions of all of our dependencies were available. This was straightforward for widely-used packages since all of them already supported Python 3. However, some packages developed specifically for RMG also had to be updated with Python 3 support, namely PyDAS and PyDQED. The second step of modifying RMG for Python 3 compatibility was facilitated by automatic tools like python-future, although substantial manual intervention was still required. In the final step, we used this opportunity to standardize function names throughout our API to comply with PEP-8 recommendations, effectively the official Python style guide. In total, transition tasks took approximately 500 developer hours to complete.