Probably nothing. The part A is usually referred to as the steering knuckle. The steering knuckle holds the strut on top, connected to the lower control arm via the lower ball joint, and the spindle is bolted to the knuckle. I would reconnect the nut to the ball joint, then hit the a-arm near the ball joint area. What is going on is the ball joint has a tapered bolt. The hole for the ball joint is also tapered. Being that they are torqued with the nut, this creates a 'fit' so there is no play. Same for the tie rod.
However, it's not a real necessity to remove the lower control arm from the knuckle to get to the spring. You do have to disconnect the strut, disconnect the tie rod and remove the caliper, then the lower control arm will have enough to swing to lower the spring.
I wouldn't have removed the strut from the spindle. This is where it's aligned. I would remove the top of the strut from the upper mount. It's only a single bolt, located withing a single hole. This wouldn't require an alignment check once you are done.
You remove the tie rod as the rack and pinion (US Vitara 3rd generation model) steering can't handle the amount of droop necessary to remove the spring.
You remove the caliper from the bracket on the knuckle as the brake line isn't long enough.
Recommendation, if you plan to install a statically taller spring, it's not going to be easy. Due to the frame point of the lower control arm and the distance of the spring from those points, it's rather difficult to get a statically taller spring in. Same for installing a larger spacer. I've tried.
To install a statically larger spring, compress it to a point near static height of stock spring. Retain it at this height. Install with PRECAUTION as the spring is now a loaded spring. Next would be to lower the factory upper strut mount. It's not easy on these models as they are rather tall and are secured with a strut mount.
Good luck.