Sorry to be the bearer of bad news, but your R4i Gold 3DS Deluxe hasn't been supported for a long time. It was shortlived after being revealed to being nothing but a Gateway Clone. If the flashcart route is the way that you wish to go, Gateway 3DS is still supported and capable of running the latest games.
The homebrew scene has evolved by leaps and bounds in the past couple years. We've reached a point where futureproofed freeware CFW can be installed using exploits. Follow the guide that was linked to install the exploits and CFW.
As for having to remove any previous hacks before installation, it only matters if you have installed patched TWL_FIRM and AGB_FIRM. Considering I know how old your current mod setup is, you don't have to worry about anything. Although, you're going to have to do the 9.2.0 Update part as well. It's all covered in the guide.
OP is coming from a much older mod setup than you're probably used to seeing. This is one thing that I wish the A9LH parrots would try to take into consideration before blindly pushing A9LH on those coming from 4.x-era mods, as sometimes extra steps need to come into play to prevent things like save data loss. In this case, OP's mod is too old for it to really come into play. However, it's an issue that gets overlooked frequently when a GW User with a 4.x SysNAND comes back to the forums looking to see what's going on after being away from the scene for months at a time.
A piece of sage advice from someone who's followed various game console modding scenes: If you're going to help someone whose mod is before your time in the scene, take the time to research it before suggesting an upgrade. There may be complications that arise from going from such an older mod that the current generation users never had to encounter.
