I would say they are comparable in difficulty to CLEP/DSST in general. Each TECEP has a syllabus page with a general description, some sample questions, suggested textbooks and sometimes a suggested online course to use for study. You register for the TECEP as if it was a course, then within the term you registered in, schedule the test with ProctorU when you're ready to take it. When test time comes you will log into ProctorU. One of their proctors will verify your identity and inspect your test taking space using your webcam, unlock the test, then monitor your screen and webcam while you're taking the exam online. It's actually easier than it sounds. You do need a decent internet connection. You can run a test of your PC and your connection on the ProctorU website.
NanoDegree: Intro to Self-Driving Cars (2019)
Coursera: Stanford Machine Learning (2019)
TESU: BA in Comp Sci (2016)
TECEP:Env Ethics (2015); TESU PLA:Software Eng, Computer Arch, C++, Advanced C++, Data Struct (2015); TESU Courses:Capstone, Database Mngmnt Sys, Op Sys, Artificial Intel, Discrete Math, Intro to Portfolio Dev, Intro PLA (2014-16); DSST:Anthro, Pers Fin, Astronomy (2014); CLEP:Intro to Soc (2014); Saylor.org:Intro to Computers (2014); CC: 69 units (1980-88)
PLA Tips Thread - TESU: What is in a Portfolio?
Coursera: Stanford Machine Learning (2019)
TESU: BA in Comp Sci (2016)
TECEP:Env Ethics (2015); TESU PLA:Software Eng, Computer Arch, C++, Advanced C++, Data Struct (2015); TESU Courses:Capstone, Database Mngmnt Sys, Op Sys, Artificial Intel, Discrete Math, Intro to Portfolio Dev, Intro PLA (2014-16); DSST:Anthro, Pers Fin, Astronomy (2014); CLEP:Intro to Soc (2014); Saylor.org:Intro to Computers (2014); CC: 69 units (1980-88)
PLA Tips Thread - TESU: What is in a Portfolio?