[Need Help] Tekkit: How to Install Optifine?

[Schmoofy_Doo]

Hello, Technic Forums! I've forgotten a lot of stuff about Tekkit since I haven't been playing for a long time, so please be nice. I just got the brand new Tekkit(The new one with Galacticraft)today and noticed that it didn't come with Optifine pre-installed. My laptop is really bad, so Minecraft can't run with decent frame rate without Optifine, let alone Tekkit. I made the following changes to my video settings:

• Changed Fancy graphics to fast
  
• changed to minimum lighting
  
• Used Max FPS
  
• Set render distance to Tiny (Since I have no optifine, there is a lot of fog which can get really annoying, so I change to Normal from time to time)
  
• Turned off Advanced Open GL
  
• Turned of VSync
  
• Turned off Server Textures
  

These changes have raised my frame rate a bit, but after a while it starts to drop again. I downloaded Optifine for Minecraft 1.5.1. I went to >AppData>Roaming>.technic>tekkitmain>bin>modpack and installed the Optifine mod there. After that, I opened up Tekkit again and guess what-no Optifine. Is there something I missed? Are there any more changes I can make to raise my frame rate a bit? I made sure that I had the right version of Optifine(1.5.1). Anyone know how I can install Optifine? Thank you!

[ulpu]

Did you delete the META-INF file? Leaving it there caused some problems for me.

[Schmoofy_Doo]

Yeah, I deleted the META-INF but Optifine still refused to work