Business objects releases, patches and upgrades

Hi AL

We are  Installing and configuring of business objects releases, patches and upgrades

SAP BO 4.0 SP 6 UPGRADE TO SAP BO 4.1 SP 5

When upgrading or installing patches for  bo 4.0 to 4.1 what servers need to be left running and stop or  disable

What other measure need to be taken before proceeding

Any other information will be very help full

Thanks

JS