What's the best way to hack the game to be easier and less grindy?

sorry if this is the wrong sub (if so please redirect me) but I've been wanting to play heartgold on my hacked 3DS through twilightmenu and I've heard SO much about how UNBEARABLE all the grinding is. I grew up on the newer games so I'm used to the game being like, actually easy. I just want the game to be less grindy and more suitable for a casual player with a low attention span y'know? anyways, I see people using an action replay to get 999 rare candies, but I 1. am playing this on a modded 3DS off an SD card and 2. don't have an action replay lmao. is there a good way to mod the game with my modded 3DS to be less grindy? like can I use a tool to mod the ROM myself or do I need to get a separate ROM hack entirely?