The i9-13900 (Non K) was delidded revealing a die size relatively larger than Alder Lake’s flagship CPU. You can thank more Gracemont cores for that.
Expreview at Bilibili removed the integrated heat spreader (IHS) from the alleged i9-13900. As shown in the picture, the die specifications come at around 23.8mm x 10.8mm amounting for a total die size of 257mm² which is roughly 23% larger than the 12900K.
No, you do not need excessive machinery for this purpose. Delidding in this case merely required a razor and a heater. Although, bear in mind delidding is a very delicate and a fragile process where even a small mistake can render your CPU useless. Most people, or enthusiasts delid to make their CPU run cooler as was shown when Linus delidding his i9-12900KS.
As per rumours, Intel plans to reveal its 13th gen CPUs on 28th September during its innovation event. Intel is expected to disclose the specifications of these SKUs along with the pricing. The alleged launch date of these CPUs and the flagship Z790 Motherboards is 17th October.