Not that hard of a tasks; assuming no prior accident damage to firewall or rails (so as to not have some reference points to work off of).

I explain some details I encountered in mine, not in any particular assembly order, but as they come to mione.

Shock Tower & Diagonal Braces: Weld-in after inner panels are positioned close to required. Both act to stiffen the inner panels; not so much as to locate them.

Radiator Upper Support: This will serve to determine spacing of inners at front/top corners. I used the oblong holes as references.

Upper Firewall Brackets: If you replaced them wrt to original markings, you should be fine.

Front Rad. Side Panels: Placement fairly simple. Bottom tabs snug into rail corners. Top: align to ref. holes in upper rad. support.

Squaring/Alignment: I used holes on top section of cowl-ls/rs: diagonally to from corners of rad support.

Buy youself a bunch of visegrips +/or c-clamps. As you'll want to temp. secure many parts together & will be repositioning frequently before any welding is started. When you start to weld parts: do only the minimal tack welding possible to secure. If any need to be relocated/moved: much easier to undo welds.