For starters, it appears that they slightly misprinted their schematic as far as the polarity of the fuel pump and coil, as if it is getting a positive connection from both sides, so-to-speak. The relays are simply a circuit-interrupt, the current flows through the contacts until the alarm triggers, pulling a low (negative ground) on the coils of both relays (86). The 85 Terminals are always connected to positive when the key is on (ACC). The diode icon on the relay shows an internal diode that "clamps" the voltage that is re-induced from the coil once it is de-energized (The collapsing magnetic field remaining actually spits out a voltage spike). This protects the transistor that most likely is turning it on. Note this, as applying the wrong polarity to the coil will be a dead short across the diode. (85+, 86- is the correct way)
I would check, both with key on and off, what side, negative or positive, remains at the Fuel Pump and High Coil. You can use a multimeter with one lead to ground, then the positive battery terminal, if possible. If the negative side, for example, is normally the switched side, cut that wire and run it to your relay contacts.(30 and 87a). By simply butt splicing additional wire to these cut ends and running these leads to the relay contacts, that saves you the ordeal of figuring out which polarity (+ or -) connect to 30, as in the drawing.
The HIGH COIL relay seems to show 86 and 30 to be together (the line coming off of the coil), but I strongly believe that to be a misprint. It makes no sense. 87 Should be LEFT ALONE. This is under the assumption that the 86 line pulls to ground ONLY during an alarm condition, as most alarms I have seen. Feel free to "meter" this wire in reference to ground to verify continuity. Relays are usually only on for the shorter duration compared to long term, but it doesnt hurt to check first. If for some odd reason the 86 lead reads "Ground" full time EXCEPT during a alarm condition, then you WOULD use 87 and leave 87a ALONE.
Hope that helps!! Reply if you have another question.