Yes the 2x4 alone will not allow a stock length shock to be removed.
I have removed complete OEM suspension and put on OEM suspension using the 2x4 method several times. It is not necessary to remove the bolt on the upper A arm, but it may make it easier (I've never tried it this way).
First make sure you have both front wheels in the air on jack stands, not just the one wheel at a time. Remove the sway bar bolts.
The 2x4 placement in the last photo will not give you proper leverage to remove the suspension. Use a small little block of wood to put on top of the rotors (if you have small children, go raid their toy box for a small wood block). This will allow you to rest the 2x4 at the 12 o'clock position without damaging the brake rotor shields.
Having the proper length 2x4 also helps. You will have to experiment wih which size works best for you. I normally just sit on the 2x4 and can control the leverage with just my weight on it. This allows me to pull it out with both hands while sitting on the 2x4. You don't want the 2x4 too long, or else it makes sitting on it very hard. You don't want it too short or you won't have enough room to sit on it.
The other trick is to put the key in the ignition and unlock the steering wheel. Roll down your windows in case you lock yourself out. With the steering wheel unlock, turn the rotors by hand (this only works if both front wheels are suspended in air). Turning the rotors almost completely to one direction (I forget which direction) will give you more clearance room to work with.
Use a large pry bar to get the bottom part of the shock out over the control arms.
If I remember correctly, try to get the bottom out first before working on the top.
Good Luck