1. Make a bin folder where you build ur files from eclipse or build script.
2. Compile your latest changes.
3. Copy everything from bin into your craftbukkit 1.4.5R0.3 jar.
4. Create a .bat file and add the following(assuming jar is named mcpc-1.4.5-beta-3) :

java -Xms2048M -Xmx2048M -jar mcpc-1.4.5-beta-3.jar -o true PAUSE

6. Play!

1. Import project
2. Right-click on MCPC-1.45-master, choose properties
3. Click Builders->Highlight compile jar->Edit
4. Change working directory to :

${workspace_loc:/MCPC-1.45-master/bin}

5. Change java location to yours. ex :

C:\Program Files\Java\jdk1.7.0_09\bin\jar.exe

6. Set arguments to (change name to anything):

cfM ../debug/mcpc-1.4.5-beta.jar *