*Note: Make sure when you copy any of these lines, that there are no spaces at the start of any line when copying it into your files
#1 In TacticalOps.ini replace all the content from
[UBrowser.UBrowserMainClientWindow] to [UWeb.WebServer] with the following: [UBrowser.UBrowserMainClientWindow]
LANTabName=UBrowserLAN
ServerListNames[0]=UBrowserLAN
ServerListNames[1]=UBrowserAll
ServerListNames[2]=UBrowserTO
ServerListNames[3]=None
ServerListNames[4]=None
ServerListNames[5]=None
ServerListNames[6]=None
ServerListNames[7]=None
ServerListNames[8]=None
ServerListNames[9]=None
ServerListNames[10]=None
ServerListNames[11]=None
ServerListNames[12]=None
ServerListNames[13]=None
ServerListNames[14]=None
ServerListNames[15]=None
ServerListNames[16]=None
ServerListNames[17]=None
ServerListNames[18]=None
ServerListNames[19]=None
ServerListNames[20]=None
ServerListNames[21]=None
ServerListNames[22]=None
ServerListNames[23]=None
ServerListNames[24]=None
ServerListNames[25]=None
ServerListNames[26]=None
ServerListNames[27]=None
ServerListNames[28]=None
ServerListNames[29]=None
ServerListNames[30]=None
ServerListNames[31]=None
ServerListNames[32]=None
ServerListNames[33]=None
ServerListNames[34]=None
ServerListNames[35]=None
ServerListNames[36]=None
ServerListNames[37]=None
ServerListNames[38]=None
ServerListNames[39]=None
ServerListNames[40]=None
ServerListNames[41]=None
ServerListNames[42]=None
ServerListNames[43]=None
ServerListNames[44]=None
ServerListNames[45]=None
ServerListNames[46]=None
ServerListNames[47]=None
ServerListNames[48]=None
ServerListNames[49]=None
bKeepMasterServer=False [UBrowserLAN]
ListFactories[0]=UBrowser.UBrowserLocalFact,BeaconProduct=ut
URLAppend=?LAN
AutoRefreshTime=10
bNoAutoSort=True [UBrowserTO]
ListFactories[0]=UBrowser.UBrowserSubsetFact,SupersetTag=UBrowserAll,GameType=TO340,bCompatibleServersOnly=True [UBrowserAll]
ListFactories[0]=UBrowser.UBrowserGSpyFact,MasterServerAddress=gsm.qtracker.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[1]=UBrowser.UBrowserGSpyFact,MasterServerAddress=unreal.epicgames.com,MasterServerTCPPort=28900,Region=0,GameName=ut
ListFactories[2]=UBrowser.UBrowserGSpyFact,MasterServerAddress=master.333networks.com,MasterServerTCPPort=28900,Region=0,GameName=ut
bHidden=True
bFallbackFactories=False [UWeb.WebServer]
Applications[0]=s_SWAT.TOServerAdmin
ApplicationPaths[0]=/ServerAdmin
Applications[1]=UTServerAdmin.UTImageServer
ApplicationPaths[1]=/images
DefaultApplication=0
bEnabled=False   #2 In Ubrowser.int replace all its content with:
[Public] [ServerListTitles]
UBrowserTO=Internet Servers
UBrowserLAN=LAN Servers


#3 In TOSystem.int replace all content with:
[Private]
Object=(Name=TOSystem.TO_BrowserServerListWindow,Class=Class,MetaClass=UTBrowser.UTBrowserServerListWindow)



Changing what version to load servers from:
In TacticalOps.ini you can select what version of Tactical Ops server must be loaded with GameType=TO340 or Gametype=TO350: [UBrowserTO]
ListFactories[0]=UBrowser.UBrowserSubsetFact,SupersetTag=UBrowserAll,GameType=TO340,bCompatibleServersOnly=True

What about the 2 other master servers?
This includes Qtracker, Epicgames and 333Network Master Servers, the other 2 are noccer.de and errorist.tk are either offline or no server report to it.

If you want to host a server, instead of editing your own files, its better to start off with the premade server package here in the download section.
(Or alternatively check out the file archive on http://TacOps.tk)