Building Inspector Findings

Our house is currently under contract, and the buyers have had a building inspection done. They have identified the following as a major issue, and the buyer has asked us to correct these before settlement. We are willing to, and I'm currently looking into plumbers, hut is this something that a moderate DIY'er could tackle? Pic 1 shows a rusted section on a down pipe.that they inspector recommended replacing. Pic 2 shows the down pipe not connected to the storm water drain.

Any advice would be appreciated.