I could not find an English translation online. However, having followed a path of searches from the Chinese version (Taisho Tripitaka Vol. 39, No. 1798), I found this from a webpage (http://mbingenheimer.net/tools/bibls/transbibl.html
) that there is an English translation:
T39n1798: Jin gang ding jing da yu qie mi mi xin di fa men yi jue 金剛頂經大瑜伽祕密心地法門義訣
e1 (T 1798: 39.808a19-b28)
“Instructions on the Gate to the Teaching of the Secret Heart of Great Yoga of the Scripture of the Diamond Tip”
translated by: Charles Orzech
In: Buddhism in Practice. Princeton: Princeton University Press, 1995. pp. 316-317.
Perhaps you can look into finding that publication?