Juniper - Hard prune and grafting?

Hello Gentleman.
Due to my lack of experience with connifers, I've decided to ask before doing anything stupid.
At my fiancee's gramma house there's a juniper (kaizuka I guess) realy old (about 40-50 years) that has great base, trunk line and even a excelent nebari.

Knowing that soon (in about 2 or 3 years) the house will put down, i've decided to save this plant after long years of desire.

The big problem is: it's over 1,7m tall and it only has green needles on the top and I want it to be with 40-50cm tops.

What I did to try solving this: self grafting. Both by thread and cleft grafting

Is there any SAFE way to to enhace base budding?

I don't have much experiencie with the species, but for I've seen in the prunning it has suffer as the years gone by is that branches without needles tend to die. Does hard (very hard) prune out of question?

I think I would first see if the tree survives the collection process, give it 12 months at least. Then you will have to consider what to do. In my experience old Junipers don't bud back well.

You might get a thread graft to work to bring the foliage lower, or attempt an air layer.

Although you are close to the equator and don't have much in the way of seasons, I think you should collect in the coldest/coolest time of year. It would be best to collect in the middle of whatever winter you have.

I would transplant to a very porous soil and keep it in the shade. You will also need to support the tree well, so that there is no movement that will break the newly forming roots.

Thanks for the reply Billy.
I've still haven't collected yet. It will stay put until the time to do so. Meanwhile I'll try to do the graftings to take.

The air layering ain't a option. The upper portion has nothing that can be used for bonsai, the only usable part is the first 40-50 cm.

I'll keep caring for it to see if the grafts succeed.

ASAP I'll try to post some pictures of it.

Thanks

Looking forward for the photos, Luiz.
Try grafting young plants and after they grow together, take away their root systems. Sorry I forgot the english term for this.