This might be a huge oversight from the developer of the mod, four years just... isn't enough time to enact all of those extremely progressive things with a relatively strong artistocracy and landowners. Especially considering this is 1836 and most nations don't even have tenant farmers yet.

The first JE is meant to be really hard, mostly because the United Republics start in a really strong position; as for the second JE, it's not that hard to complete,and as soon as you keep turmoil low, you have infinite time.

It's doable, just a lot of RNG, you can go for either fast civil war against slavers or
1 DONT CLICK THE STARTING EVENT it will add JE at its own after 90 days, it's 3 months free time
2 supress pro-slavery movement
3 bolster abolitionist movement
4 set taxes very low
5 include inteligentsia and rural folk in goverment, find combination that gives you most legitimacy
6 pick political ideas from national focus tab
7 try to get generals and admirals from inteligentsia IG, or anything to weaken landowners clout
8 hope for abolitionist devout leader and assasination JE for landowner president
I suggest making a save after getting slavery banned in decent amount of time because landed voting is tricky, I got it with 1year 10 months left in JE and it managed to be just enough.

I HIGHLY RECOMMEND PLAYING THEM, they are just too op after you complete the JE, USA on steroids, the rest of laws go really smooth after this JE.