Seal for Small Window

[awdsvx]

Just wondering if any of you ever had to replace their seal that runs on top of the small window? If so, is it easy to do it yourself? I have already placed my order, it is comming from Japan and is going to take like 3-4 weeks. Anyway just wondering..., here is the seal I am talking about, I high-lighted it in yellow. The seal that I have on my SVX, there is rust built up underneath and it is bubbling up throgh the rubber. Thanks in advance for what ever advice you can give me.