Player wants to go from Ranger to Artificer
One of my players (first timer) wanted to multiclass into Artificer after reaching level 4 in the campaign now (originally 3 levels in ranger). He doesn't have enough INT but I am pretty rules light (especially when it comes to player wanting things like this) so we talked for a while and landed on his character over the next ~5 sessions going through an arc. At the end of this it would be narratively sound for him to respec to whatever artificer build he wants.
While we are both happy with the slight rule bending without it feeling too "hand wavy" I was wondering if anyone had gone through something like this before - how best to handle it/any pitfalls I could come up against. Or just offer advice based of DM wisdom after hearing about the circumstance.
TLDR: player go from ranger -> artifice in story/rules how