I have the wrong SMT 74HC373s, but they somehow work. The chip is too wide, meh.
What you are SUPPOSED to do is get one of the SMT rework stations that blow hot air to melt solder. The guys on chiptuners say that the chinese units work well, I dunno as I've never used one. Anyway:
1) *glue* the SMT chip into the correct position
2) paint a stripe of solder paste (it's powdered solder mixed with flux in a syrette) across the contacts of the chip. For these ECUs, two thin lines of the paste, one on each side.
3) hit the chip with the hot air, the solder melts and flows and beads up on the individual contacts without bridging the contacts. It's pretty cool.
What I do is get one of the cheap irons and sharpen the tip to a fine point with a grinder. I melt a little solder onto every pad, glue the chip to the board, then place the iron on top of each pin in turn to melt it down. Ghetto as hell, only done maybe five of them in my life, but it works.
This may sound like a stupid question, but can that knock board be removed if the 'knock sensor' is disabled?
Yes.