how to represure combi boiler worchester 24i?

Combi boiler worchester 24i has lost pressure have seen all those handy videos and read n read up after 3dys of cursing an threatend with hammer, there is no hole 4key which i bought along with loop still no were to put them in/on only see 2 drain values running along skirtin 4ft away,does it need either? any help wod b great b4 boiler gets the hammer! An im up 4murder!